#ifndef __TIME_STAMP_H
#define __TIME_STAMP_H
#include<cctype>
#include<string>
class TimeStamp
{
private:
    int64_t secondSinceEpoch_;
public:
    TimeStamp();
    TimeStamp(uint64_t secondSinceEpoch);
    std::string ToString() const;
    static TimeStamp Now();
};
#endif